1. Field of the Invention
This invention relates to textile quality fibers of sulfonated poly(p-phenylene terephthalamide). The fibers of this invention can be dyed to deep shades rapidly and without need for a carrier. They exhibit ease of crimp and other desirable qualities.
2. Description of the Prior Art
U.S. Pat. Nos. 4,075,269 and 4,162,346, issued Feb. 21, 1978 and Jul. 24, 1979 to Jones et al., disclose the spinning of low inherent viscosity sulfonated poly(p-phenylene terephthalamide) into fibers. Jones et al. teach that the sulfonated polyamide can be prepared from the appropriate sulfonated diamine or diacid derivatives or mixtures thereof. Alternatively, poly(p-phenylene terephthalamide) (PPD-T) may be sulfonated according to Jones et al. using either concentrated sulfuric acid or fuming sulfuric acid. The as-spun fibers of the Jones et al. patents exhibit single filament tenacities of about 10 grams per denier, an elongation of about 2.5% and an initial modulus of about 200 grams per denier. Jones et al. heat treat the as-spun fiber to achieve tenacities of at least 15 grams per denier, an elongation of at least 1.5%, e.g. 2-3.5% and a modulus of at least 400 grams per denier. Such fibers are high performance fibers not of textile quality.